In recent years, various antennas built in mobile device casings, namely, built-in antennas and electronic device casings including the same, have been widely studied. At present, there are various antenna technologies such as in-mold antennas (press type), plated antennas (laser type), press assembled antennas (press assembly), printed antennas (print type), etc. that respectively have their own advantages and disadvantages.
A conventional in-mold antenna is generally mounted on a frame of a mobile communication device. The space between a feeding portion (electricity feeding portion) formed on a frame and a position in which the antenna pattern is formed, is completely sealed. In addition, since the pattern is not formed on the outermost portion of the frame, it is easy to form a new antenna pattern on the frame. However, in comparison with a technology in which the antenna pattern is formed at the outermost portion of the frame, the antenna pattern that is not formed on the outermost portion of the frame is close to the ground because the antenna pattern is formed inside of the frame. Therefore, it is difficult to obtain superior performances such as good reception sensitivity, radiation performance, etc. In addition, it is difficult at the development stage to modify the antenna pattern formed inside of the frame. That is, a total amount of the antenna pattern may be limited depending on the structure of the frame. Consequently, antenna performances are degraded as much as the antenna pattern is limited.
In addition, in the conventional plated antenna (laser type) or the printed antenna, the antenna pattern may be formed at the semi-outermost portion of the mobile device, but it is difficult to form the antenna pattern at the outermost portion of the mobile device.
In addition, the plated or printed antenna is configured such that a connecting part between the feeding portion and a point at which the antenna pattern starts is formed by plating. Therefore, a hole may occur at the connecting part, and thus it is difficult to seal the connecting part.
In the conventional press assembled antenna (press assembly), the antenna pattern may be formed at the semi-outermost and outermost portions of the mobile device. However, the antenna pattern is only formed at an area in which the antenna radiator is not exposed to the outside of the battery cover of the mobile communication device. Therefore, transmitting and receiving sensitivities are limited due to the small coverage of the antenna radiator. That is, the antenna radiator is typically only formed on an upper surface of a FPCB, and is not formed on a side surface that is not covered by the battery cover. Thus, there is a limitation in extending the size of the antenna radiator.